Characterization of Comb Shaped MAA‐co‐PEGMA Copolymers Synthesized by Free‐Radical Polymerization,Macromolecular Reaction Engineering

当前位置： X-MOL 学术 › Macromol. React. Eng. › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

Characterization of Comb Shaped MAA‐co‐PEGMA Copolymers Synthesized by Free‐Radical Polymerization
Macromolecular Reaction Engineering ( IF 1.8 ) Pub Date : 2020-05-27 , DOI: 10.1002/mren.202000015
Iñaki Emaldi ₁ , Amaia Agirre ₁ , Agustin Etxeberria ₂ , Edurne Erkizia ₃ , JorgeS. Dolado _{4,

5} , Jose R. Leiza ₁

Affiliation

Methacrylic acid‐co‐polyethylene glycol methacrylate (MAA‐co‐PEGMA) copolymers (also known as MPEG‐type polycarboxylate ether (PCE) superplasticizers) present comb‐shaped microstructure and they are generally used as dispersants of inorganic particles in cementitious formulations. Application properties of the PCEs strongly depend on the molecular structure and therefore accurate characterization of the microstructure is necessary to fully understand the structure–property relationship. In this work, MAA‐co‐PEGMA copolymers with various lateral size chain lengths and homogeneous copolymer compositions are synthesized by starved‐feed semibatch copolymerization. Molar mass and radius of gyration distributions and monomer sequence distribution are measured using size exclusion chromatography coupled with multi angle light scattering (SEC/MALS/refractive index, RI) and ¹H and ¹³C NMR, respectively. Furthermore, it is proved that the experimental radius of gyration compares well with the prediction of a theoretical model for the radius of gyration that uses characteristic parameters of the microstructure of the PCEs (e.g., average molar masses). This confirms the accuracy of the measurements of the absolute molar masses for the MPEG‐type PCEs synthesized by free‐radical (co)polymerization.

中文翻译：

自由基聚合合成梳形MAA-co-PEGMA共聚物的表征

甲基丙烯酸-共-聚乙二醇甲基丙烯酸酯（MAA- co- PEGMA）共聚物（也称为MPEG型聚羧酸酯醚（PCE）高效减水剂）具有梳状微观结构，通常在水泥配方中用作无机颗粒的分散剂。PCE的应用特性在很大程度上取决于分子结构，因此准确地表征微观结构对于充分理解结构与性质的关系是必要的。在这项工作中，MAA-合作通过饥饿进料半间歇共聚法合成了具有各种侧向尺寸链长和均相共聚物组成的‐PEGMA共聚物。摩尔质量和回转半径的分布以及单体序列的分布分别使用尺寸排阻色谱法和多角度光散射法（SEC / MALS /折射率，RI）以及¹ H和¹³ C NMR进行测量。此外，已经证明，实验的回转半径与使用PCE的微观结构的特征参数（例如，平均摩尔质量）的回转半径的理论模型的预测很好地比较。这证实了通过自由基（共）聚合合成的MPEG型PCE的绝对摩尔质量的测量精度。

更新日期：2020-05-27

点击分享查看原文

点击收藏

阅读更多本刊最新论文本刊介绍/投稿指南11